Another basic fairing shape question.
 

I've been considering the advantages of sliding "doors" or closures on the sides of a fairing of the Vetter /Zero type but that throws up the problem of "side lift" without the pressure equalisation across the bodywork.

I'd appreciate opinions on whether a straight sided shape with the rounding on the faces forward but nor the sides ( as a Vetter would appear from square on the side) but with sliding "doors" would be a good idea. The flat sides would strongly reduce side lift in cross winds and traffic buffetting . The tail would continue to a Kamm ending.

It's the last that worries me most, large truck trailers combined with a cross wind would create all kinds of crazy patterns.

Any ideas ?

edited to add, i note Allert's 214 mph Inova has essentially flat sides ,slightly rounded but with a quite long flat section in the middle.